Compressible strip material, such as fiberous glass insulation, can be removed from a conveyor and packaged in a belt roll-up which uses a loop to help roll the insulation pack upon its self. The length of the belt is controlled as the material is fed into the loop so that the package reaches its final predetermined diameter at the time the end of the pack enters the loop. The length of the belt, and thus the size of the loop, is allowed to grow as the pack is fed into the loop by a means which places the belt drive into contact with the pack at a faster rate than it removes the belt from the loop. The operatiton of belt roll-up equipment is well known in the art. See, for example U.S. Pat. No. 3,911,641.
One of the important considerations in packaging flexible strip material, such as fiberous glass insulation, is the need to avoid over-compression of the material. Fibers are bonded together with organic binder, and over-compression of the pack results in breaking the glass fibers and/or rupture of the bonds between the glass fibers. This results in a much lower recovery or free expansion height of the pack after it is unpackaged in its ultimate destination, such as, for example, an attic of a house. The lower recovery and lesser thickness of an over-compressed pack results in a lower total resistance to heat flow and a lower R-Value. It has also been shown that repeated compression of the insulation material degrades its thermal performance. If a pack is compressed, allowed to expand, and then recompressed, its thermal properties will be degraded. Thus, it is desirable to provide a packaging method allowing the maximum compression of the insulation material while avoiding degradation of the insulation value through damage to the recovery properties of the pack.
In order to avoid over-compression of the pack, and to prevent inadvertent expansion and recompression immediately prior to rolling up the insulation pack, it has been proposed to provide a compression member, such as a compression chute to maintain the pack in compression immediately prior to feeding the pack into the roll-up apparatus. This proposed solution is only partially satisfactory, because it requires a positioning of the chute tip close enough to the roll that the tip interferes with the front or leading edge of the pack during the initiation of the roll of the pack. This problem is particularly prevalent when the pack has a facing of such materials as foil or paper, because the facing strikes the chute tip and the pack is damaged. Thus, this one proposed solution to the expansion and recompression problem has resulted in a problem of wool delamination and peeling back of the facing of the leading edge of the wool.
If the compression chute is moved back away from the roll-up apparatus, then the wool can expand before entering the roll-up apparatus, forming a zone of expansion or "bubble". The problem caused by the "bubble" of wool expansion between the chute tip and the roll is that the top surface of the bubble scrapes against the belt, which is traveling in the opposite direction. This scuffing action results in degradation of the surface appearance of the pack and contributes to product dustiness.